Lift for automobiles



June l2, 1934. c. J. BRISTOL LIFT FOR AUTOMOBILES 2 Sheets-Sheet l Filed Oct. 29, 1930 Hh" s June 12, 1934 c. J. BRISTOL 'l LIFT FOR AUTOMOBILES Filed 0013. 29, 1930 2 Sheets-Sheet 2 Patented June I2, 1934 LIFT FOR'AUTOMOBILES Cyrus .I. Bristol, Des Moines, Iowa, assignmto Globe Machinery &

Supply Company, Des

N Moines, Iowa, a corporation of Iowa Application October 29, 1930, Serial No. 491,934

2 Claims. (Cl. 254-93)` v The object of this invention is to provide an improved lift for automobiles or the like; and especially designed for use in connection with relatively long and heavy automobiles, such as buses.

More specifically it is my object to provide a lift of this character having two fluid pressure jacks permanently fixed in upright positions, andA to provide a superstructure designed to engage and support the vehicle being lifted, and to so connect the superstructure to .the jack'stthat the superstructure may be raised and lowered while maintaining a horizontal position, or may be tilted to any desired degree of inclination.

A further object is to provide manually controlled means whereby fluid pressure may be supplied to both jacks for the purpose of raising tand lowering them simultaneously or fluid pressure may be applied to either of the jacks independently ofthe other to tiltthe superstructure to any desired inclination.

A further object is to provide means for aur. tomatically controlling the fluid pressure admitted to or exhausted from both jacks,'-whereby they will be simultaneously raised or lowered to maintain the superstructure in a substantially horizontal position throughout its entire movement.v

This invention consists in the construction, ar-

rangement and combination of the various parts 30 of the device, whereby the objects contemplated are attained, as hereinafter more fully set forth, pointed out in the claims, and illustrated in the accompanying drawings, in which:

Figure 1 shows a side elevation of a lift embodying my invention with the jacks permanently. fixed in upright positions.

Figure 2 shows a top or plan view of same and illustrating the means for controlling the air pressure to the two jacks.

Figure 3 shows a vertical central sectional view through one of the 'jacks illustrating the structure of the cross head at the top of the jack and lthe means for pivotally supporting the superstructure thereon.

Figure 4 shows a detail sectional view taken on the line 4-4 of Figure 3.

Figure 5 shows an enlarged detail vertical sectional view illustrating the controlling arm and connected parts for actuating 'the exhaust valves.

Figure 6 shows a detail sectional View illustrating the counterbalancing and pressure exhaust valve, kand taken 'on the line 6-6 of f Figure 4.

Figure l` shows anl enlarged detail sectional view illustrating the pressure equalizing cham- (U ber with its exible diaphragm and controlling valve.

Figure 8 is a sectional view of one of 'the control valves.

Figure 9 is a sectional View of another control ou Valve. 4

Referring to the accompanying drawings it will be seen that there are two fluid lpressure jacks,- one at each end of the lift. Each jack comprisesv upright cylinder 10 and a piston 11 vertically 65- movable in the cylinder. At the top of each piston there is a cross head indicated generally by the reference numeral 12, and firmly xed in position at the top of the piston. FixedA in this cross head is a shaft 13 with its ends pro- 70 jected beyond the cross head. y

The superstructure for receiving and supporting a vehicle comprises two parallel rails 14 rigidly connected together at their central portionseby a cross brace 15, At each end of each of the rails 14 there is ahorizontally arranged slot I6 through which the projecting ends of the shaft 13 are extended, and a collar 17 is detachably xed to each outer end of each shaft 13 to engage the outer surface of the adjacent rail 14. Mountv8o ed up'on the rails 14 are the chairs 18 designed to receive the axles or other portions of the vehicle to be elevated.

From the foregoing it will be seen that whe fluid pressure is applied to the two jacks in proper proportions, the superstructure will be elevated and maintained in a horizontal position, and when iiuid pressure is exhausted from the cylinder in proper proportons, the superstructure will be lowered while maintaining a substantially hori` 90 zontal position. However, in many instances it is desirable to tilt the superstructure when wholly or partially elevated, and when this is done the superstructure has a pivotal and sliding connection with the cross heads at thel tops of the pistons, which will permit the superstructure to be tilted at any angle within the range of the pis-l tons without tilting the pistons from their upright position or exerting vany undue strains upon either the superstructure or' the pistons.

For the purpose of raising and lowering the superstructure either in a horizontal position, or tilting it' to various angles, I have provided the following manually controlled means.

The numeral 19l indicates a supply pipe con- 105 nected with a suitable source of iiuid pressure supply. Communicating with the pipe-19 are two pipes 20, one leading to each cylinder." Communicating with each of the p ipes 20 is an exhaust pipe 2l. In each of the pipes v20 there no spring closed and each has a projecting pin 37 v ,equalizing device.

is provided a hand operated valve 22 for controllingthe admission of fluid pressure to the pipe 20 'and in each of the pipes 21 there is a hand operatedvalve 23 for controlling the exhaust of fluid pressure from ,the pipe '20.

Hence, when both the exhaust valves 23 are close'd, and both the fluid pressure supply valves 22 are open, fluid pressure will be supplied in substantially equal amounts to both pistons to simultaneously raise them, and when both of the valves 22 are closed and the valves23 are open,

fluid pressure will be exhausted from both cylin-A ders in substantially the same amount.

In' connection with this hand controlled operation of the. pistons, it '-is obvious that if for any reason one piston moves faster than the other, and the superstructure is thereby moved out of horizontal position, this can readily and easily be corrected by simply manipulating the proper one of the valves 22 or 23.

I have provided means for automatically maintaining the superstructure in a substantially horizontal position vduring its entire movement, and for this purpose I have provided in the iiuid pressure supply pipe 19 a controlling valve 24, and a three way lowering valve 25. When the valve 24 is open and the valve 25 closed, and in the position shown in Figure 9, then fluid pressure is admitted to the pipes.20, but when the valve 24 is closed and the valve 25 open, then iiuid pressure is exhausted from the`ppes 20 through the valve exhaust port 25a.

In each of the pipes 20 there is a needle valve 26 and between the pipes 20 is a pressure equalizing device indicated generally by the numeral 27, and having a iiexible diaphragm 28. Connected to this flexible diaphragm and projected outwardly through the sides thereof are the movable needle members 29 of the valves 26. 'I'hese parts are so arranged that when the diaphragm is moved to the right as shown in Figure 7, then the needle valve 26. in the pipe 20 at the right is closed, and the one at the left is opened. ,Y

For supplying uid pressure to the equalizing device 27 I have provided a pipe 30,communicating with the supply pipe 19 and having two branches 31, leading to kopposite sides of the A valve 32 is provided in the pipe 30 for opening or closing the passage through it.- y

By means of this construction it will be seen that when the valve 32 is open, iiuid pressure will be applied to opposite sides of the equalizing device in substantially equal amounts, and the needle valves 2,6 will remain open to permit the passage of iiuid under pressure through the pipes 20. o

For the purpose of equalizing the exhaust pressure from the cylinders, I have lprovided at the lower end ofthe equalizing device two pipes 33 communicating with a two-way valve 34, which valve 34 communicates with two pipes 35 leading to two exhaust valves 36 fixed to one of the superstructure rails 14. These valves 36 are extended toward each other but spaced apart.

For the purpose of actuating the valves 36 to control the exhaust from the cylinders, I have provided on one of the`cross heads 12 a horizontally arranged arm 38 having a joint at.39 and above and below this joint are springs 40 for normally holding the free end of the arm in a substantially horizontal position, but on account of said springs, the free end of the arm is capable of yielding movement to a limited extent. The free end of the arm 38 is projected between the valves 37, and two pins 41 are-fixed to the rails 1 4 to limit the movement of y,the free end of the arm 38.

In practical use with this portion of the device and assuming that the v alve 34 is in position to' permit communication between the valves 36 and the pressure equalizing device 27, then so 'long as the rails 14 remain in a substantially horizontal position, the free end of the arm 38 is held in about the position shown in Figure 6 relative to the valves 36. When, however, the rail 14 is tilted in either direction, the free end of the arm 38 is caused to press upon one or the other of the valve pins 37 and open it. This will permitthe air to exhaust from one side of the equalizing chamber 27, and thus move the diaphragm toward the same side, thus closing the exhaust `passageway throughthe corresponding valve 26 thus retarding the iiow of air through the exhaust valve 25. On the other side of the vequalizing device, the needle valve 26 is correspondinglyA opened so that anv increased drop in pressure is applied to the opposite cylinder,` and this condition continues until the rails 14 again ,become approximately horizontal.

When the superstructure is being elevated, the valve 34 is moved to one open position, and when the superstructure is being lowered, the valve 34 is opened to another position, to re verse the connection between the 'pipes 33 and 35 so that a given valve 26 will move toward a closed position as the lift is lowered for restricting the downward movement of the lift, and to an open position as the lift is elevated to increase the power applied to the lift. i

In practical use it will be seen that when the valves are properly arranged for automatically maintaining the superstructure in a horizontal r positionl during elevation, no matter how much excessive weight is placed on one end or the other of the superstructure, the requisite amount of uid pressure is provided for each cylinder to raise its proportionate share of the load, and the arm 38 through the exhaust valves 36 automatically maintains such pressures in the cylinderas will hold the superstructure in a substantially horizontal position during its entire upward movement. Correspondingly when it is desired to lower the device, the valve 34 is moved to open positionI and the valve 25 moved to open position, the valve 24 is closed, and when being lowered, the superstructure .will maintain its horizontal position, and in the event that at any time'it is -desired to tilt the superstructure, the valve 32 may be closed and the hand valves 22 or 23 may be manipulatedto effect the desired tilting operation.

I claim as my invention:

1.In a lift of the class described, the combination of two iiuid pressure jacks, a superstruc- `mitting to or exhausting from each jack iluid under pressure, means for automatically controllingthe uid pressure to'maintain the superstructure in a substantially horizontal plane during its vertical movement, said means comprising a controlling arm xed to one of the jacks, two uid pressure controlling valves carried by the superstructure and so positioned relative to said controlling arm that one orthe other of said valves will be actuated by the arm when the superstructure is tilted from a hori- 150 zontal' position, means for operatively connecting each o! said valves to said means tor admitting to or exhausting from each Jack fluid under pressure, to thereby tend to return the superstructure to approximately horizontalposltlon.

2. In a lift of the claas described, the combination of two iluid jacks. a superstructure designed to support a vehicle pivotally and slidably connected to each jaclr, means for admitting to or exhausting from each jack fluid under pressure, a controlling arm ilxed to one of said jacks, two fluid pressure controlling valves carried by the superstructure and so positioned relative to said controlling arm that one or the other of said valves will be actuated by the arm when the said superstructure is tilted from a horizontal position. a pressure equalizing device having 'a exible diaphragm and having its sides opposite said diaphragms communicating with said valves, means for admitting fluid under pressure to both sides oisaid diaphragm, fluid conducting means for communicating each side oi said diaphragm with a corresponding one of said valves whereby actuation of one of said valves will cause said diaphragm to be actuated, and means operated by the actuation oi said diaphragm for controlling the pressure applied to said Jacks by means of the means i'or admitting to or exhausting from each .lack iluid under pressure.

CYRUB 'J. BRISTOL. 

